This invention relates to a sounder. In particular, it relates to a sounder for an alarm system such as a fire or intruder alarm system.
EP 0509840 discloses a sounding device for using such a system in which an electrical sounding device is mounted in a housing and spaced a distance from a sounder plate so that sound is generated by the sounding device and is directed away so that the sound emerges laterally. The sounding device is one which may have a further electrical device, such as a detector or a light, mounted on top of the sounder. The device is arranged so that the sounder plates lies between the mounting part for the sounder and any additional detector or other apparatus. Thus, if the sounding device is attached to a ceiling, the sounder faces away from the ceiling.
It is desirable to encapsulate components such as electronic components and also the sounders in such devices and, with the apparatus shown in EP 0509840 it is necessary to use two encapsulation processes. The sounder must be encapsulated from its rear (ie. from the surface nearest the ceiling or other support) and the electronic components are encapsulated from the upper side.
The present invention arose in an attempt to provide an improved sounder of the type which can be used on its own, or with an additional electrical component mounted on it.
According to the present invention there is provided a sounder assembly comprising a housing, means for providing a sounder plate; a base for attaching the sounder assembly to a support surface such as a ceiling or wall, and an electrical sounder mounted generally within the housing, the arrangement being such that, in use, the sounder plate is spaced from the housing and is located between the housing and the support surface, with the sounder facing the sounder plate such that sound is generated towards the sounder plate and is directed away from the housing so that the sound emerges generally laterally of the sounder plate, and wherein the centre of the sounder is displaced from the centre of the sounder housing.
Thus, the sounder is positioned to emit sound initially towards the ceiling or other support surface, ie the sounder is inverted.
Preferably, the sounder plate is integral with the base.
The sounder is preferably positioned at an angle other than 90xc2x0 to axis of the assembly.
The sounder plate is preferably concave and the sounder is positioned at a position displaced from the centre of the housing at an angle which generally matches (ie is generally parallel to) the angle of the sounder plate at that position.
According to the present invention there is further provided a sounder assembly including any one or more of the novel features described herein.